Saguaro cactuses tower over ... Saguaros grow slowly. A young cactus may grow just 1 to 1.5 inches in its first eight years of life. The amount of water available affects their growth.

Saguaro cactuses ... in 1986. The cactus was likely 150 years old. The National Park Service confirms this record on its website. Saguaros grow slowly. A young cactus may grow just 1 to 1.5 inches in ...